Bloch waves in periodic multi-layered acoustic waveguides
Bloch waves in periodic multi-layered acoustic waveguides
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DOI：
10.1098/rspa.2008.0065
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发表时间：
2008-10
期刊：
影响因子：
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通讯作者：
Samuel D.M. Adams;R. Craster;S. Guenneau
中科院分区：
文献类型：
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作者：
Samuel D.M. Adams;R. Craster;S. Guenneau
在沿波导沿着具有周期性结构而又保持有限宽度的声波导和电磁波导中，给出了带谱和相应的Floquet-Bloch本征解，沿波导壁沿着采用齐次Dirichlet或Neumann条件，或交替采用齐次Dirichlet或Neumann条件。重要的是，在某些情况下，在零频率处的总阻带被识别为低频局部模式提供空间;结构化波导中的几何缺陷也产生这些模式。数值和渐近技术确定色散曲线和捕获模式。有些情况下，布里渊区内的光谱边缘的最大值和最小值，也允许超低光或声音。成像应用异常色散产生亚波长分辨率是可能的，并证明。
The band spectrum and associated Floquet–Bloch eigensolutions, arising in acoustic and electromagnetic waveguides, which have periodic structure along the guide while remaining of finite width, are found. Homogeneous Dirichlet or Neumann conditions along the guide walls, or an alternation of them, are taken. Importantly, in some cases, a total stop band at zero frequency is identified providing space for low-frequency localized modes; geometric defects in the structured waveguide also create these modes. Numerical and asymptotic techniques identify dispersion curves and trapped modes. Some cases demonstrate maxima and minima of the spectral edges within the Brillouin zone and also allow for ultraslow light or sound. Imaging applications using anomalous dispersion to generate subwavelength resolution are possible and are demonstrated.